From 13fa7d49d9dff588599ec0f5c70c4ac34b47dca1 Mon Sep 17 00:00:00 2001 From: Mark Qvist Date: Mon, 19 Dec 2022 01:15:49 +0100 Subject: [PATCH] Added automatic path rediscovery on failed link establishments --- RNS/Transport.py | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/RNS/Transport.py b/RNS/Transport.py index c773626..e029613 100755 --- a/RNS/Transport.py +++ b/RNS/Transport.py @@ -66,6 +66,7 @@ class Transport: PATH_REQUEST_TIMEOUT = 15 # Default timuout for client path requests in seconds PATH_REQUEST_GRACE = 0.35 # Grace time before a path announcement is made, allows directly reachable peers to respond first PATH_REQUEST_RW = 2 # Path request random window + PATH_REQUEST_MI = 5 # Minimum interval in seconds for automated path requests LINK_TIMEOUT = RNS.Link.STALE_TIME * 1.25 REVERSE_TIMEOUT = 30*60 # Reverse table entries are removed after 30 minutes @@ -92,6 +93,7 @@ class Transport: announce_handlers = [] # A table storing externally registered announce handlers tunnels = {} # A table storing tunnels to other transport instances announce_rate_table = {} # A table for keeping track of announce rates + path_requests = {} # A table for storing path request timestamps discovery_path_requests = {} # A table for keeping track of path requests on behalf of other nodes discovery_pr_tags = [] # A table for keeping track of tagged path requests @@ -285,6 +287,7 @@ class Transport: @staticmethod def jobs(): outgoing = [] + path_requests = [] Transport.jobs_running = True try: @@ -384,10 +387,18 @@ class Transport: if time.time() > link_entry[0] + Transport.LINK_TIMEOUT: stale_links.append(link_id) else: - # TODO: Decrease timeout for invalidation and path re-request - if time.time() > link_entry[0] + Transport.LINK_TIMEOUT: + if time.time() > link_entry[8]: stale_links.append(link_id) + last_path_request = 0 + if link_entry[6] in Transport.path_requests: + last_path_request = Transport.path_requests[link_entry[6]] + + # TODO: Check that we are local client shared instance + if time.time() - last_path_request > Transport.PATH_REQUEST_MI: + RNS.log("Retrying path resolution for "+RNS.prettyhexrep(link_entry[6])+" since an attempted link was never established", RNS.LOG_DEBUG) + path_requests.append(link_entry[6]) + # Cull the path table stale_paths = [] for destination_hash in Transport.destination_table: @@ -518,6 +529,9 @@ class Transport: for packet in outgoing: packet.send() + for destination_hash in path_requests: + Transport.request_path(destination_hash) + @staticmethod def transmit(interface, raw): try: @@ -1003,15 +1017,19 @@ class Transport: outbound_interface = Transport.destination_table[packet.destination_hash][5] if packet.packet_type == RNS.Packet.LINKREQUEST: + now = time.time() + proof_timeout = now + RNS.Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, remaining_hops) + # Entry format is - link_entry = [ time.time(), # 0: Timestamp, + link_entry = [ now, # 0: Timestamp, next_hop, # 1: Next-hop transport ID outbound_interface, # 2: Next-hop interface remaining_hops, # 3: Remaining hops packet.receiving_interface, # 4: Received on interface packet.hops, # 5: Taken hops packet.destination_hash, # 6: Original destination hash - False] # 7: Validated + False, # 7: Validated + proof_timeout] # 8: Proof timeout timestamp Transport.link_table[packet.getTruncatedHash()] = link_entry @@ -1211,9 +1229,9 @@ class Transport: retransmit_timeout = now + (RNS.rand() * Transport.PATHFINDER_RW) - if packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ACCESS_POINT: + if hasattr(packet.receiving_interface, "mode") and packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ACCESS_POINT: expires = now + Transport.AP_PATH_TIME - elif packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ROAMING: + elif hasattr(packet.receiving_interface, "mode") and packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ROAMING: expires = now + Transport.ROAMING_PATH_TIME else: expires = now + Transport.PATHFINDER_E @@ -1386,10 +1404,11 @@ class Transport: # Handling for linkrequests to local destinations elif packet.packet_type == RNS.Packet.LINKREQUEST: - for destination in Transport.destinations: - if destination.hash == packet.destination_hash and destination.type == packet.destination_type: - packet.destination = destination - destination.receive(packet) + if packet.transport_id == None or packet.transport_id == Transport.identity.hash: + for destination in Transport.destinations: + if destination.hash == packet.destination_hash and destination.type == packet.destination_type: + packet.destination = destination + destination.receive(packet) # Handling for local data packets elif packet.packet_type == RNS.Packet.DATA: @@ -1849,6 +1868,7 @@ class Transport: on_interface.announce_allowed_at = now + wait_time packet.send() + Transport.path_requests[destination_hash] = time.time() @staticmethod def path_request_handler(data, packet):